BeagleBone Green Hands-On: Lower Price, Same Horsepower

Although the BeagleBone Green was announced at the Bay Area Maker Faire last May, there hasn’t been much said about it on the usual forums and IRC channels. Now, it’s finally out and I got my hands on one of them. Through a cooperation between the BeagleBoard foundation and Seeed Studios, the best small Linux board for doing real work with small Linux boards is now cheaper, a little more modern, and green.

The BeagleBone Green is an update to the venerable BeagleBone Black, the dev board based on a TI ARM Cortex-A8. It’s an extremely capable machine with a few interesting features that make it the perfect device for embedded applications. With the BeagleBone Green, the BB Black gets a small hardware refresh and a drastic reduction in price. If you want to do real work on a Linux board, this is the one to get. Check out the review below for everything that’s been updated, everything that’s the same, and why this is one of the most interesting developments in small Linux boards in recent memory.

The Differences From The BeagleBone Black

The BeagleBone Black and BeagleBone Green back to back

The BeagleBone Black has been around for more than two years now, but it’s still an extremely capable machine. The BeagleBone Green borrows heavily from the Black, with a few changes to satisfy the cost-reduction goal, and to make the BB Green slightly more accessible.

By far the largest change is the removal of the microHDMI connector. This is accompanied by a large bare spot on the board where the NXP HDMI Framer chip once was on the BB Black. When I talked to [Jason Kridner] his justification for the removal of the HDMI capability of the Green was that ‘nobody used it.’ This is fair and true; if you want a media server, you get a Raspberry Pi, and if you want a tiny Linux box to toggle pins very quickly, you get a BeagleBone. The removal of HDMI plays to the BeagleBone’s strengths, and makes it a less expensive board. You can’t argue with that.

Also on the list of changes are the addition of two Grove connectors. These connectors are part of a modular system of electronics that put a UART or I2C bus on a single connector. With these connectors and a few modules from the Grove System, building simple projects is a snap. The addition of two Grove connectors – one UART, one I2C – is Seeed’s largest contribution to the BeagleBone Green, and with a large catalog of parts ranging from simple logic gates to OLED displays and GPS modules, it’s pretty handy.

Grove modules, like this OLED display, are plug and play with the BeagleBone Green

Aside from those changes, the BeagleBone Green is pretty much exactly the same as the BeagleBone Black. It has the same amount of RAM, the same processor, the same amount of eMMC Flash, and the same pinout as the BB Black. The Green moves to a USB micro connector for the power and serial connection. This had been USB mini on the BeagleBone Black. That’s a welcome change that’s long overdue. The barrel jack for power has been removed from the BeagleBone Green, and the larger USB port has been moved right next to the Ethernet socket.

As is the case with the BeagleBone Black, the Green comes with the Cloud 9 IDE already installed on the Linux image on the eMMC. This is a cloud-based IDE, but is hosted on the BeagleBone. For a device that really isn’t meant to be a desktop computer, this is the easiest way to get code up and running on a tiny Linux box. Combine this with a serial terminal, and it’s really all you need.

Why It’s Great

Although the BeagleBone Black has been around for a while now, and the BeagleBoard even longer, the Beagles have been playing second fiddle to the Raspberry Pi forever. This is a shame. The Raspberry Pi is not the ideal tool if you want real-time control of a lot of pins, and the GPIO expansion on the Pi is more of a kludge than something it was designed for.

The removal of the HDMI port in the BeagleBone Green doesn’t make this board any less capable. Like I mentioned above, nobody used it anyway. Add to that the fact you can buy an LCD cape for the BBG – and have it work with the 3D accelerator – and you’re really not losing any capability, just shaving sixteen bucks off the price. The BBG will launch with a $39 price tag, or about the same price as a Raspberry Pi. While it won’t impress many people that want a cheap Linux box for retro video game emulation, it is a great board for anyone who wants to get real work done.

Interesting. If I remember correctly, one of the main improvements in the Beaglebone Black compared to previous Beaglebones was the onboard HDMI. Now they’ve decided that actually, they don’t need it after all? Seems a bit odd.

I’m using X forwarding via SSH to view the LinuxCNC GUI. It works well in my opinion (under Linux that is, using XMing and Putty for Windows is terrible), the only issue being that it takes something like 15 seconds for the BBB to load the GUI and another 10 seconds to change gcode files. Also, I hope they decide to keep the two variants.

Machineface gets around the need for HDMI with machinekit. you can run it as a service, and then remotely control with your phone, computer, tablet, etc. best part is, nothing needs to stay running, no need to worry if your ssh tunnel fails.

The HDMI gets in the way of using all the cape pins. For a project at work we ended up shelling out extra for a few BBWs for this reason. That and the built-in USB JTAG + serial console it has over the BBB is a bonus.

Last year I was trying to decide between BBB and RPi, and ended up picking RPi, for two reasons
– faster HDMI (so the video’s less likely to flicker)
– operating system on the SD card, so it’s much easier to update/fix/replace if I want to do something different or hose the system.

What’s the deal with Grove connectors?! There are so many REAL connectors– you know, ones with part numbers and datasheets– that can be ordered from lots of vendors, but this and the Bean+ (also covered on HaD today) chose Grove. Why??? They’re sort of like JST PH except they’re not. GRRRRR.

I despise those connectors. It’s disappointing to find them in a board where real, standard connectors should be. I’m not buying cutesy “Grove” versions of the components I need to connect to the dam board.

I actually started my journey into Linux with the original Beaglebone and the Beaglebone Black but quickly moved to the Raspberry Pi. The two reasons for this were:
– The PRU (which is one of the major selling points of the Beaglebone soc) was very difficult to use and had very little ‘good’ documentation on how to use it. I’m not sure if this is still the case or not.
– The whole ‘you can’t apply a voltage to the GPIO pins until the board powers-up’ rule. This is mentioned in the BBB’s manual. This means that I have to add additional hardware to make sure that this requirement is met…which in my mind is an unnecessary hassle.

Don’t assume you can safely apply a voltage to pins on any other CPU just because they didn’t explicitly forbid doing so in the manual. The norm is that you can’t.

There is not much to write about the PRUs. It is sad that the official PRU documentation is on a website instead of the AM335x TRM, but everything is there (apart from the industrial features, i.e. EtherCat & co.).

Yep. Unless stated otherwise, you shouldn’t ever apply a voltage to a pin that is greater than the supply voltage which would be zero in this case. If your chip requires multiple voltages to power it then check the datasheet to find out the correct order to bring them up.

If you overshoot the supply rails or bring up the voltages in the wrong order then you can get latchup and burn out the chip. It may not always happen either so your prototype might be fine but once you start mass production then you’ll find some devices just mysteriously die.

Problems usally come from clamping/protection diodes or other parasitic diodes directy at the output pin, between the buffers and the outside world. Apply a voltage to the pin, and the current wants to go thru the top clamping diode into the supply net. Depending on how much punch your external supply delivers, this can quickly vaporize not just the diode, but other stuff in the chip too.

There are buffers, and they are tristated but there is still ESD diodes, if you power pins on an IC that isn’t powered you will push current through the ESD diodes and in worst case trigger latch-up so the IC will short the supply and smoke once you turn on power. Some IC can handle more current than others but you shouldn’t do it

Same for me. I had the original one and it had problems booting Linux, the guys in the iRC channel and mailing list ignored me totally. I’d love to use the PRU if it was supported. The PRU is the killer feature of these boards. The DSP on board my original one was unsupported. I never trusted Ti CPUs after the dropped the OMAP like a rock, orphaning the phones that used it. Their radio chips CCXXXX are fantastic and have superb support. In the end I threw my original one in the electronics recycling bin. That’s green.

CC3000 was a complete scandal. Many people reports bugs with the firmware. A simple TCPServer hangs after only few hours. TI never followup those bugs, and after more than one year, they answered “change your design to use the newer CC3200” …

haha, OK, I am really talking about the 11XX series. People seem to like the 3300 though, aside from the fact that’s it’s multiple times the price of competitors. That’s said, I don’t trust them anymore. I’d actively avoid their parts in design.

Except, it’s not. At least the product page hasn’t changed and there’s no new product entry in the bazaar.

I’ve been waiting for this damn board for over 2 months now. Multiple emails to Seeed support asking for ETAs only to get multiple answers when the previous date passes. I still can’t believe it took this long to get a price for the thing.

Hopefully they’ll actually allow us mere mortals to purchase the Green after all this waiting and I am glad to see that it isn’t vaporware.

Pity for that change of the USB connector and removal of the barrel jack. It is not like they were limited by space or costs (both cost peanuts), so why to remove these? If the BBB is going to be really embedded somewhere, then the jack is easier to find (or put on) on a power supply than a micro USB connector. The micro USB connector is also extremely flimsy – I see its point in a cell phone where every millimetre of thickness matters, but here? It is probably the worst USB connector when long time mechanical reliability is concerned.

I’m so disappointed they’ve removed the HDMI. Now the Raspberry PI has a true monopoly on credit card computers. The Beagle Bone Green isn’t even a true computer any more, because without a display you need another computer to develop on it. Worse still, you can develop for Beagle bone Green using a R-PI, but you can’t develop for R-PI using a Beagle Bone Green. Good grief, you could probably even program a Beagle Bone Green using a FIGnition, but not the other way around!

I’m excited for this version. I’m firmly in the camp that never used the HMDI port. 8 PWM pins on the BBB is sexy. The only thing I’m disappointed by is the difficulty of programming the PRUs. If they made it easier to program those the BBB would be the maker tool of choice hands down. As for the HDMI, I think you could probably get an addon board to re-add that functionality as the pins are exposed through the headers I think.

this is fantastic, recently as a hobby i have been researching can bus/ iso bus hacking in agriculture, isoblue.org is a great place for information and they use BBB, a can bus shield and a bluetooth adapter to send can bus information to an android device. RTK with a BBB.

long time lurker, first time poster, hackaday is my second favorite website

These days I use a Banana Pi Pro for everything that power intensive. It costs slight more than the BBB and RPI, but the performance is amazing, and it doesn’t suffer from all the fatal usb/hdmi flaws in the RPI.

I applaud the removal of the HDMI port (for the sake of cost reduction). I haven’t owned a TV since 1999. I’m a “engineer” (software, just tinkering with hardware), so _of course_ I have a couple of PCs with USB ports. For me setting up the BBB (tethered to the PC via USB) was the easiest solution by far. My Raspberry PIs are operating headlessly, the BBG makes more sense there (except perhaps for the one I use as Internet radio, there multiple USB ports are useful).

you say that you can attach a LCD display cape and have it use the video acceleration, but if the HDMI is removed, is there still video acceleration on the system? there shouldn’t be.

I join those who think that having a version with HDMI is good, but having a different version without is also good. There are now third parties producing the BBB, so the BBG isn’t going to eliminate it as an option.